The default software settings for the Oculus CV1 remap the color space so that areas that should be a deep black instead are displayed at a higher brightness level. Because of this remapping, a black image may not produce complete darkness and near-black objects may lose their shading. The effect is less noticeable in a scene with bright and flat illumination, and it may not be noticeable in many applications. But for the types of imagery we use, this remapping can be annoying.
The remapping may have been done as an attempt at a software fix for an optical problem. In the CV1 model, Oculus switched to using a partial fresnel lens design, which reduced weight and improved focus at the perimeter of the display. Fresnel lenses have problems with lens flare, which is even more apparent in the full fresnel used on the HTC Vive. Reducing contrast ratio decreases the visibility of the flares. Oculus apparently decided that reducing the flares was more important than having a full color range, so they ship the CV1 using the compressed color space by default.
The ideal solution would be to allow the applications running over the HMD to control the remapping, so that the developers could pick the optimum trade-offs for their scenes. The reasons why Oculus does not allow this are not clear - perhaps they did not trust their developers to make good decisions or they did not want to adjust their GPU code at the whim of the apps using their service.
Instead, their support staff provides a "spud remover" to customers who complain which sets a registry value that is read when the service starts and can disable the color remapping. For convenience, we distribute this tool with our application so you can enable or disable the 'spud' from the file menu.
Depending on the permissions configuration on your machine, we may not be able to adjust the Oculus service from within our application. In that case, you will have to run the batch file from a command window yourself. To do so, use Windows file explorer to go to the VmsPlayer folder where our app is installed, which is typically "C:\Program Files (x86)\VMS\VmsPlayerInstall" and then open the VmsProgramResources folder. Right click on SpudOff and select "run as administrator". Clicking on SpudOn will restore the default Oculus color space.